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OS: Windows 2003STD x64 en
I have try to call python method from c++ dll by "WINFUNCTYPE".
But the 4th parameter is always None or 0 if the type is int or void* (float is works fine).
Following is the part of source code:
==code==========================================
import sys
from ctypes import *
windll.LoadLibrary("testPy2.dll")
#########################################
def test3(param1,param2,param3,param4,param5,param6,param7,param8,param9,param10):
 print("================")
 print(param1)
 print(param2)
 print(param3)
 # the 4th param4 is always 0.
 print(param4)
 print(param5)
 print(param6)
 print(param7)
 print(param8)
 print(param9)
 print(param10)
 print("================")
 return 20
 
C_METHOD_TYPE4 = WINFUNCTYPE(c_int32, c_int32, c_int32, c_int32, c_int32, c_int32, c_int32, c_int32, c_int32, c_int32, c_int32)
windll.testPy2.fntestPy7(9,C_METHOD_TYPE4(test3))
==code==========================================
To my knowledge, both visual c++ and gcc use registers for the first few parameters, and then after that use the stack. Maybe this is the reason.
I have attached some simple codes for reproduce this issue.
issues
 - testPy2 <- source code of the dll
 - test.py <- python file to reproduce the issue
 - testPy2.dll <- the dll to reproduce the issue